Ocean in a Bottle

An ocean in a bottle is fairly quick and simple to make. Since "quick & simple" is my middle name, this project was one of my favorites as a kid. Five minutes' work will yield an attractively hypnotic "ocean." It's also a fun use and a second chance for an old plastic bottle.

This is my first instructable--suggestions welcome. Onward--->

Supplies:

Step 1: Materials

What you'll need:

-->a plastic bottle {I'd recommend 1 liter or smaller for weight's sake}-->water-->food coloring-->mineral oil (any oil will do, but this one is nice n' colorless; it can be procured at a drugstore for a reasonable price)-->water insoluble glue-->a funnel {not pictured}

Optional:-->scissors-->electrical or duct tape

Step 2: Adding the Water

Once you have your materials, remove the label from the bottle. You may need scissors for this. Or not.

Next, fill the bottle about half way up with water and decide what color you want it to be. I was out of red and yellow, so I settled on a teal hue (two drops green, three blue). Add the food coloring and give the bottle a light swirl to mix.

Step 3: Oil Time

Here's where that funnel is going to come in handy.

Slowly fill the rest of the bottle with your oil. The funnel with prevent the oil from getting all over the outside of your bottle and rendering it hopelessly slippery (I know from experience). Come as close to the top as possible without spilling.

Step 4: Seal It!

Now to seal in the goodness.

Basically you're just going to screw on the cap as tight as you can. I put some glue on the threads of the bottle before closing as added insurance.

You can also wrap some electrical/duct tape around the cap as further protection against leaks if you feel so inclined.

My daughter is off school today (gas leak!) I think we'll make this today. What might stabilise the oil to prevent it becoming lots of little globules if shaken too hard? - or has anyone found what type of oil serves best?

Excellent question, and one to which I wish I had the answer as well! I had one of the store bought variety on my desk one time and someone came up and shook it. As they were shaking it, they asked what happens if someone shakes it!!! Ijit! I told him he had to buy it from me then! It was never the same after that: the oil and water never completely separated, and the little bit of air mixed with the oil permanently as well. If you get an answer, let the rest of us know!!! Please!

I recommend NOT using vegetable oil. It can spoil and turn rancid. We made an ant barrier for my mother's hummingbird feeder, and she filled it with olive oil the first time. Some few months later, ants invaded the feeder and investigation revealed that the oil went rancid, turning thick and gelationous... the ants could then walk right across it! After cleaning it up and refilling with mineral oil, it generally lasts at least a year before getting too full of miscellaneous debris and needing to be cleaned and refilled again, but the mineral oil remains liquid.

...of course, being sealed in a plastic bottle will keep air and microbes from getting to the vegetable oil and it might last a really long time if you're lucky. But unless you sterilize everything and work very carefully to keep it that way, there's no way to be sure.

I dunno if u could use more than 2 types since water oil don't mix due to density AND polarity... there's only polar (e.g. water) and non-polar (e.g. oil)...so the two that were both (non)polar they might just mix once u shook it up (even if they had different densities)... but like i said i dunno... :P

#3: hydrophobic liquid that's denser than water. This is the tricky one. I've seen tetrachloroethylene recommended for this purpose on DIY lava lamp websites, but it's also bad for you, so you would need to do this whole thing in a glass container AND make sure the container never breaks. https://en.wikipedia.org/wiki/Tetrachloroethylene